I flew CSA to JFK last Saturday and I noticed liquid dropping from the A310's wing only moments from takeoff - never seen that before. I guess that's kerosene dropping from a kind of spillover outlet? Can anyone comfirm that?

I don't know much about the A310, but fuel overflow is usually centralized in the form of a drain mast or overflow valve on the wing or body. It wouldn't just seap out over the distance of a wing like that. Fuel can slightly increase in size due to heat and that could cause it to overflow if the plane has been sitting in the sun, but that doesn't seem like the case.

Water is a good guess for when the flaps were retracted. It could have been raining when the plane landed and it accumulated water in there.

If you have never designed an airplane part before, let the real designers do the work!

In general, when an aircraft vents fuels, not leaks, it will come from, the vents near the wingtip. This area, the surge tank, is usually a dry are that can contain the fuel. It will drain back to the mains, if there is enough room, but will dump on the ground if the fuel has nowhere to go.

Another possibility, albeit a remote one, is that some of the water drain valves are partially stuck open. These valves allow mechanics to drain off any water that accumulates in the bottom of the fuel tanks. Despite being multi-million dollar machines, Airbus seems to fit the cheapest drain valves it can source. Many times I have had to muck around trying to get those valves to shut properly.

Regards, JetMech

JetMech split the back of his pants. He can feel the wind in his hair.

if it was a cold morning it could possibly be deicing fluid that had been sprayed on. if not then i would go with the others and say its water. the last thing i would think would be fuel. If it was fuel then this aircraft has big problems

Quoting Wirelock (Reply 8):if it was a cold morning it could possibly be deicing fluid that had been sprayed on. if not then i would go with the others and say its water. the last thing i would think would be fuel. If it was fuel then this aircraft has big problems

Yes, as you can see in the picture conditions are perfect for being deiced?

I have many wing components, Panels, canoe fairings, wing tips and what they ALL have in common are "Wheep Holes"...They are 3/8th holes located in the lowest point of above mentioned components so residual water(condensation, rain water, washing and deicing fluids will be siphoned out during flight. They are not as effective on ground as flaps and fairings typically should be extended for better run-off...Once aircraft in flight low pressure areas suck the moisture out...G

Quoting Spencer (Reply 15):What actually causes the spillage though, does the valve have to be open during such conditions, (High OAT/full tank)?

Not sure about the details of the C130 fuel system but, typically, there is a surge tank in the wing tips connected to the fuel tank vent system. If a tank overfills, the fuel backs up the vents into the surge tank. The surge tanks is open to the atmosphere all the time and, if the surge tank gets too full, the fuel drools out the surge tank vent.

The picture of the C130 shows fuel draining from the Fuel Jettison nozzle and NOT the fuel vent system. On the Herc the fuel vent system outlet is actually underneath the wings via 2 outlet manifolds (you can just make them out in the picture approx 10 feet inboard from the wingtip). This phenomenon on the C130 was quite normal after having landed from a flight where fuel jettison has taken place. When fuel jettison takes place the Fuel Jettison pumps from each of the tanks pressurises the Fuel Jettison manifold which runs along the length of both wings. In the outboard drybays (behind the outboard engines) there is a Wingtip Jettison Valve which when selected open by the Flight Engineer opens the valve and the pressurised fuel is ported to the nozzle in the picture.
When fuel jettison is complete the Jettison pumps are selected off. However the Jettison manifold which runs the length of the wing is now filled with unpressurised fuel. The Flight Manual states that 'if time permits and it is safe to do so cross-control the aircraft to remove the excess fuel from the manifold'. After having done this the FE closes the Wingtip Jettison Manifold Valve. However ther is still always some residual fuel left over and after landing it was normal to see a small amount of fuel drain out due to wing droop and taxying around corners.
Whether this is the reason for the fuel draining from this aircraft as I've described above is debatable, as the wing flaps are in the Take Off position and the APU is shutdown (which would indicate they may be taxying for Take Off), however the flaps may be on their way up when the picture was taken and the APU yet to be started??

Flap Fairings are giant water collectors and when they select flaps down, the water comes pouring out the drains. Rule number one when in the hangar for maintenace....don't stand or put your tool box near the flaps or you will get soaked.

"It's not the size of the dog in the fight, but the size of the fight in the dog"

Hi Spencer. If the C130 is departing for Take Off and is porting fuel out of the Wingtip Jettison nozzle it is unusual. I should also mention that the refuel manifiold and the jettison manifold are the same piece of plumbing. When the single point refuel is connected and refueling commenced fuel pressurises the refuel/jettison manifold and the refuel operator opens and closes the tank fill valves accordingly to fill the tanks. When the refuel is complete a 'drain' of the manifold must be completed, which takes approximately 3-5 minutes and drains approximately 200lbs of fuel from this manifold into the No3 main tank.
This would however still leave a small amount of fuel and a high vapour content in the manifold afterwards. Obviously the Wingtip Shutoff Valves are closed at all times on the ground otherwise fuel would pour straight overboard during a refuel.

During combat operations we carried out a procedure to ensure a complete purge of the refuel/defuel manifold of excess fuel and vapour. This would prevent any nasty surprises in the event of taking small arms fire from causing a possible explosive force if passing through this manifold. This was in conjunction with suppresant foam in the fuel tanks. This procedure called for the Wingtip Shutoff Valves to be openned and left open for the duration of the sortie in a combat zone. After the Valves were opened, the Pilot Flying would cross-control (sidelip left and right) the aircraft and remove all of the excess fuel and vapour. However it was normal for this procedure to take place in flight after the After Take Off Checks were completed, otherwise fuel may port overboard (as in your picture).
In some cases this procedure was carried out on the ground when departing directly into a 'hot' zone.

Who knows if this is the case in your picture. I am only making assumptions??

When I flew older C130E's many many years ago, there was an entry in the Flight Manual that stated that if there was in excess of 7500lbs of fuel in Tanks 1 and 4, fuel may be seen to port overboard from the Wingtip Jettison Nozzle. This was caused by the manifold which connected the Wingtip Shutoff Valve and the Wingtip Nozzle passing through the outboard tanks (1 and 4) from the outboard drybays. As it was located in the upper portions of the tank it would be submerged in fuel (until fuel was consumed down from 8995lbs to approx 7500lbs) and place the wigiflex couplings (couplings that connect lengths of plumbing and allowed flexing with the wing bending forces) under fuel. These older wigiflex couplings were notorious for leaks and resulted in similar situations as in the picture. This did happen to me occasionally (not very often though) and usually disappeared when airborne and the wing flexed upward. The C130H which I flew later did not have this problem. I assume a more efficient coupling was designed and fitted between the C130E and H??

However the aircraft in the picture is not a C130E and most likely a C130H!!